Skin tissue generally comprises three distinct layers including the epidermis, the dermis, and the hypodermis or the sub-cutaneous layer.
The epidermis is the surface layer of the skin tissue and the thickness of the epidermis depends on a number of factors, including age, sex and the location on the body. For example, the skin on the bottom of the foot can be up to 30 cell-layers thick, while the skin on the eyelids is extremely thin. About 90 percent of the cells in the epidermis are keratinocytes, designated because they produce a characteristic fibrous protein called keratin, which provides many of the skin's protective properties. The bottom section of the epidermis, called the basal layer, contains melanocytes, which produce melanin—the skin pigment.
The dermis layer is positioned immediately beneath the epidermis and is connected by a continuous membrane. The dermis forms the thickest section of skin tissue and contains blood vessels, white blood cells, nerve endings, hair follicles, sweat glands and sebaceous glands. Fibroblasts constitute the main cell type in the dermis and they provide a source for collagen and elastin, the fibrous proteins that form the primary structural components of the skin tissue. The dermis provides moisture to the epidermis, produces collagen and elastin to maintain the structural integrity of the skin tissue, and contain glands that produce sebum to keep the skin supple and hydrated.
The hypodermis or the sub-cutaneous layer beneath the dermis, is composed of an extensive network of connective tissue and is imbued with fat cells. It acts as a protective cushion and helps to insulate the body by monitoring heat gain and heat loss. The sub-cutaneous or the hypodermis layer is some times not considered as part of the skin tissue.
Correction of tissue defects including functional, cosmetic, and aesthetic defects have primarily focused on injecting or implanting non-biological materials such as saline and silicone or processed biological materials such as isolated and cultured fibroblasts or other tissue cells. Introducing non-biological material or biological material derived from another source, for example, bovine collagen or cultured fibroblasts, may result in adverse reactions in the individual.
Therefore, there exists a need for simpler and practical procedures to repair tissue defects, including skin defects and for a device to process the tissue to enable repairing the defective tissue. The present disclosure provides methods to process a suitable tissue using a tissue grinder and to reintroduce the processed tissue to correct or repair the defective tissue site.